AF, firms seek UAV flights in civil air space - Air Force News | News from Afghanistan & Iraq - Air Force Times

AF, firms seek UAV flights in civil air space

A few U.S. companies are developing optionally piloted aircraft in the realization that it could be many years before unmanned planes are smart enough to replicate the ability of a human pilot to sense other air traffic and avoid it, a capability the Federal Aviation Administration is insisting upon before treating unmanned aircraft like traditional planes.

Aurora Flight Sciences of Manassas, Va., has converted general aviation Diamond DA42 planes into optionally piloted aircraft in hopes of selling them as intelligence, surveillance and reconnaissance planes. Mav6 has designed the Air Force’s football field-length Blue Devil 2 airship to accommodate a pilot when necessary. Northrop Grumman and its Scaled Composites unit in Mojave, Calif., flew their optionally piloted Firebird at the 2011 Empire Challenge intelligence-sharing demonstration in Arizona, albeit in the piloted mode.

Having a pilot aboard would give customers more flexibility to move an aircraft from one site to another to train operators, patrol borders and aid police.

But while experts see niches for these planes, they suggest the aircraft are more a symptom of the problem than a solution to a more fundamental issue facing the U.S. military: what to do about the hundreds of Predator-class unmanned aircraft and the handful of high-flying Global Hawks that might be returning to the U.S. as the country pulls out of Afghanistan.

The Air Force will need to fly sorties out of U.S. bases to keep those aircraft and their operators sharp.

“We’re going to bring aircraft back from Iraq and Afghanistan, and we’re going to train in the [continental U.S.],” said Steve Pennington, the Air Force’s director of ranges, bases and airspace, and executive director of the Defense Department’s FAA policy board. “So the challenge is how to fly in nonsegregated airspace.”

The Air Force and FAA agree there should be no restrictions on unmanned aircraft flying at altitudes between 18,000 feet and 60,000 feet, known as Class A airspace. At those altitudes, all aircraft — manned and unmanned — operate under instrument flight rules, which means the pilot relies primarily on instruments to control the plane within a flight plan filed with the FAA. Those instruments can be in the cockpit or, in the case of unmanned aircraft, in a ground control station. Either way, air traffic controllers are responsible for maintaining safe distances between aircraft operating under IFR.

Below 18,000 feet, pilots are permitted to use visual flight rules, which allow them to look out of the cockpit to navigate and avoid other aircraft. Under VFR, safe separation is the responsibility of the pilot, who does not have to communicate with air traffic controllers, except near controlled airports and some busy areas. There is also controlled IFR traffic below 18,000 feet, but pilots of those aircraft still must look out for uncontrolled VFR traffic. However, the military’s unmanned aircraft do not have the ability to “sense and avoid” nearby aircraft. So below 18,000 feet, the FAA allows drones to fly only in narrow, segregated flight corridors or in areas for which special permission has been granted.

The Air Force can’t install sense-and-avoid equipment on the Predators because the necessary gear — radars, infrared cameras, transponders — is either too big or consumes too much power. A Predator equipped with sense-and-avoid equipment “can’t carry anything else,” said Dave Bither, Mav6’s vice president for strategic development. “Right now, the technology is a generation away.”

With that in mind, the Air Force is trying to convince the FAA that, in the short term, readings from ground radars can be sent to pilots in ground control stations. These radar readings would serve as the core for a ground-based sense-and-avoid system.

The FAA has agreed to work with the Pentagon on the ground-based proposal, but it expects the radars to have limited impact on the problem.

“From a practical standpoint, the ground-based sense-avoid is likely to be much more of a localized solution,” said an FAA official, who spoke on condition of anonymity. “Radar can only reach out so far.”

Les Smith, the FAA’s flight technologies and procedures division manager, said the agency’s biggest technological challenge is sense and avoid, although “we welcome anything [the Air Force] comes up with.”

The Air Force is pushing the radar concept because it wants to avoid creating columns of restricted airspace around UAV bases. Restricting more airspace would disrupt civilian air traffic and defeat the service’s effort to normalize unmanned operations.

For the next five to 10 years, the Air Force wants to use existing ground-based air traffic control radars and other long-range search radars already in the Air Force inventory, Pennington said.

“We’d repurpose current existing ATC and long-range radars and provide a picture to the crew in the GCS that shows both the cooperative and noncooperative” aircraft, Pennington said, referring to radar icons that display the identity information broadcast by aircraft, and those that are unidentified. “What the ground-based sense and avoid is designed to do is to provide you coverage until you get into Class A airspace, or if we’re going to continue transiting below 18,000 feet.”

Around the service’s RQ-4 Global Hawk base in Grand Forks, N.D., for example, the Air Force has created a transition airspace zone, but it would return that airspace to civil users once the ground-based sense-and-avoid system is in place, Pennington said.

The reliance on radars would not require a large leap of faith, Pennington said. It would be relatively easy, he said, to monitor air traffic in narrowly focused corridors in which unmanned aircraft flew predetermined courses.

But that would be a short-term solution. If unmanned planes are to operate with few restrictions, the Air Force will either have to come up with a way to more closely monitor all of the airspace inside the U.S. or find an airborne solution, Pennington said.

“Airborne sense and avoid is the follow-on,” he said.

That follow-on, Smith said, is “much more attractive and preferred.” However, it will be much more difficult to develop and build.

There are two hurdles, Pennington said. With the possible exception of the Global Hawks, the Air Force’s unmanned planes don’t have enough electrical power and volume to accommodate sense-and-avoid equipment. The Navy is taking the lead on sense-and-avoid technology under its Broad Area Maritime Surveillance program, in which Northrop Grumman is developing a variant of the Global Hawk for ocean surveillance.

The FAA is particularly concerned about the size, weight and power issues, Smith said. The vast majority of unmanned planes are fairly small and fly under 18,000 feet, he said.

The Defense Department has looked at airborne radars and airborne camera systems. But the FAA’s Automatic Dependent Surveillance-Broadcast apparatus — for which every aircraft is equipped with a next-generation transponder that would transmit aircraft data such as altitude, velocity and separation — is gaining favor as the basis of a Defense Department airborne sense-and-avoid architecture. This technology is in development under the FAA’s Next-Generation Air Transportation System.

“Probably the greater capability over time is going to be the ADS-B,” Pennington said.

However, the FAA is not sold on the ADS-B for airborne sense and avoid for unmanned aircraft, Smith said.

“I would say from the FAA perspective, we’re open to industry to come up with a technical solution to sense and avoid,” he said. “We’re not limiting the technology, but we haven’t endorsed any particular technology.”

The second hurdle as Pennington sees it is that the Air Force and the FAA also need to come to an agreement on lost command link procedures.

“Our concern with the command-and-control link is the reliability and integrity of that link itself,” Smith said. “The second part would be predictability of the aircraft when that occurs.”

Secure vs. lost control link

From the Pentagon’s perspective, the challenges of a secure control link and lost control link are well understood.

Pennington said unmanned planes have an advantage over manned aircraft in some respects. There have been cases of civilian airliners missing their destinations and flying on to different areas, he said. Although pilots of manned aircraft are supposed to be in constant contact and obeying the directions of air traffic controllers, human error or equipment failure can cause an aircraft to lose contact. When that happens, air traffic controllers have no idea what to expect from the aircraft, he said.

But when a pilot in a ground control station loses the command link to an unmanned aircraft, he can contact air traffic controllers and tell them what the aircraft will do. A Predator, for example, is programmed to enter a predictable orbit if the command link is lost.

Moreover, if a pilot becomes incapacitated in a ground control station, another pilot is immediately available to take over, Pennington said.

The next step in development is autonomy, Pennington said. That would enable the aircraft to operate independently if the link is lost or if there is increased satellite communications lag, he said. There are also experiments ongoing with artificial intelligence that would be able to fly the aircraft in the complicated national airspace. In the overwhelming majority of current nongeneral aviation manned aircraft, the flight management system already flies the plane under most circumstances. Pilots have to intervene if something out of the ordinary happens, which is the same as it would be in an unmanned aircraft.

“The only challenge there is: How do I work with my controller friends so that they know what to expect?” Pennington said.

The main disagreement is whether the aircraft should maintain a continuous data link with the ATC and give advance notice of its intentions, or if it would operate like a normal aircraft, he said. Additionally, the system would need to be integrated into the FAA’s system.

The companies working on optionally piloted planes have their own challenges with the FAA.

“In the developed world, the FAA in the United States and similar organizations in Europe and other places, there are no certification specs for an unmanned airship,” Bither said of Mav6.

So Mav6 has made it so the craft can accommodate a pilot.

“Say you’re going from the continental United States to an island in the Caribbean or someplace overseas and you want to self-deploy, you would put pilots onboard,” Bither said.

The company has been working with the Air Force and the FAA, but Bither said it is apparent the two agencies didn’t see the approaching demand for operating unmanned planes in civil airspace.

“If you put a pilot onboard, you mitigate that,” he said.

Northrop Grumman sees a similar solution in Firebird.

“It offers tremendous flexibility because it is designed as both a manned platform, to fly just as any manned platform would fly in national airspace, combined with the persistent multirole capability of an unmanned system when that time comes,” said Rick Crooks, Northrop Grumman’s Firebird program director.

Effectively, planes like the Firebird are two aircraft in one, he said. Because a pilot can be sitting in the cockpit monitoring the aircraft’s activities and can see outside and react to air traffic nearby, operators can train and fly in a training area or fly in civil airspace like any other plane, Crooks said.

“The pilot onboard will do the see-and-avoid job that’s required to access congested airspace without special clearance,” he said.

Phil Finnegan, an analyst at the Teal Group consulting firm in Fairfax, Va., said he does not see a large market for the optionally piloted planes.

“They are addressing niche requirements, such as for a UAV that can be moved easily despite FAA and other flight restrictions,” he said.

He said he also sees niche applications for militaries or special forces operating in areas that can’t accommodate the launch and recovery equipment required for some unmanned planes.

“Although the number of optionally manned aircraft being offered has grown, as yet there have been few buyers of optionally manned aircraft,” he said.

Militaries around the world do not have requirements established for these types of aircraft, Finnegan said.

“They are not thinking in terms of aircraft that can be used manned or unmanned,” he said. “Procurements are generally written for either manned or unmanned aircraft. Getting that to change requires a change in the way procurements are structured in different countries.”

Although there is little interest in the Defense Department for optionally piloted aircraft, there is one conspicuous exception. The Air Force’s new long-range strike bomber will be optionally manned, Chief of Staff Gen. Norton Schwartz and Secretary Michael Donley have often repeated.

“When it comes to an Air Force bomber, optional manning might offer the advantage of avoiding putting personnel at risk in high-risk operations,” Finnegan said.